Control of conditioned environment by remote sensor

ABSTRACT

A comfort HVAC or refrigeration system includes a remote sensor for sensing an environmental condition within a climate-controlled space and having, an associated transmitter for sending, a wireless signal to a receiver of a controller such that the controller can then responsively modulate the operation of the components of the HVAC or refrigeration system to maintain a desired condition at a specific location or locations within the-climate-controUed&#39;space. The desired condition can be, for instance, temperature, humidity and/or carbon dioxide level.

TECHNICAL FIELD

This invention relates generally to comfort HVAC (heating, ventilation,air conditioning) and refrigeration systems and, more particularly, to amethod and apparatus for maintaining desired parameters, such astemperature and humidity, within a climate-controlled space while usingremote wireless sensors.

BACKGROUND OF THE INVENTION

Heating, ventilation, air conditioning and refrigeration (HVAC&R)systems are designed to maintain predetermined conditions in a space.These conditions are primarily related to a desired temperature range,but other conditions, such as humidity level and carbon dioxide content,for example, may be controlled as well. This is generally accomplishedby the use of one or more dedicated sensors positioned within the space.

Currently temperature and/or humidity sensors are installed within thespace at fixed secure locations, and/or hard wired to a control that iseither located within the space or outside the space. For example, in abuilding, the sensor may be associated with a thermostat which istypically mounted on the wall, with wiring passing to a control thatresponsively activates components of the HVAC system such as a furnaceand an air conditioner. In a refrigerated enclosure or a container, oneor more sensors are located at specific secured locations within therefrigerated container and are hard wired to a control which is normallylocated outside of the refrigerated space of the container. However, ineither case, the location of the sensor is not necessarily the locationwhere the temperature needs to be measured and controlled. For example,in the building, the temperature needs to be controlled in the nearvicinity of a person or a number of people who ale the occupants of theclimate-controlled environment. In a container, the temperature needs tobe controlled in the particular portion of the space in which the cargoresides or within the cargo itself and not at the specific fixedlocation at which the sensors have been originally installed. Theselimitations can be overcome by the present invention.

DISCLOSURE OF THE INVENTION

In accordance with the present invention, a wireless sensor or sensorsare selectively positioned within a space to be conditioned orrefrigerated and include a transmitter for communicating a sensedenvironmental condition to a receiver associated with a controller,which responsively actuates components of an HVAC&R system. In this way,the one or more sensors may be selectively positioned to satisfy thecomfort or thermal load requirements and provide precise control ofenvironmental conditions at any desired location in an efficient manner.An environmental condition sensor may include, but is not limited to, atemperature sensor, a humidity sensor, a carbon dioxide sensor of acombination thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a sensor and a control inaccordance with the present invention.

FIG. 2 is a schematic illustration of a refrigerated enclosure inaccordance with the present invention.

FIG. 3 is a schematic illustration of a comfort HVAC system inaccordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a remote wireless sensor 11 and an associated control 12 inaccordance with the present invention. The sensor 11 is designed tosense an environmental condition, such as temperature or humidity,within a space such that the control 12 can responsively operate anHVAC&R system so as to maintain that condition within a predeterminedrange.

In order to communicate the sensed condition to the control, the sensor11 is provided with a transmitter 13, and the control 12 is providedwith a receiver 14. The transmitter 13 and receiver 14 can be of anywireless type such as, for example, a radio frequency device. Such awireless arrangement allows for selective placement of one or moresensors within the space to be conditioned as will now be described.

As is seen in FIG. 2, a refrigerated enclosure 16 is provided with anassociated refrigeration unit 17. In transport applications, therefrigeration unit 17 is typically mounted on the front end of therefrigerated box 16 and provides conditioned air to the refrigeratedenclosure 16 that is typically circulated over the top and through therefrigerated cargo 18, with the air then passing along the floor, andpartially along the sides, back to the refrigeration unit 17 to bere-conditioned and re-circulated into The refrigerated enclosure 16.Rather than the one or more sensors being hard wired and positioned atspecific secure locations of the refrigerated enclosure 16, a pluralityof remote wireless temperature sensors 19 are selectively located withinor in the vicinity of the cargo 18, and communicate in a wireless mannerwith a controller 21 that is typically positioned within therefrigeration unit 17 so as to control the temperature and/or volume ofair flowing to the refrigerated enclosure 16, in order to maintain therefrigerated cargo 18 at a temperature within a predetermined range.

In this manner, the refrigerated cargo 18 is Maintained at apredetermined temperature, and over-cooling, as well as insufficientcooling, of the refrigerated cargo 18 is avoided, regardless of theposition of the refrigerated cargo 18 within the refrigerated enclosure16. Furthermore, if the refrigeration unit 17 is capable of providingvariable air volume or variable airthrow, the refrigerated cargo 18 canbe kept at a sufficiently more uniform temperature in response to thefeedback of the remote wireless temperature sensors 19 to the controller21 of the refrigeration unit 19, in order to avoid potential spoilage orloss of the product quality. Such sensor-controller communication alsoallows for a more efficient operation and lower energy consumption forthe refrigeration unit 17.

It should be understood that that remote wireless temperature sensors 19may be installed in addition to the primary sensors associated with therefrigeration unit 17 to provide correlation between the air temperatureand airflow/airthrow supplied to the refrigerated enclosure 16 and thetemperatures within the refrigerated cargo 18, or they may be theprimary and only sensors providing feedback to the control 21 of therefrigeration unit 17.

In FIG. 3 there is shown a typical residential building 22 with twoclimate-controlled spaces such as rooms indicated at 23 and 24. Acomfort HVAC system 25 may include an air conditioner or heat pumptypically comprising outdoor and indoor units 26 and 27, respectivelyunits and a furnace 28, the latter typically installed to provideheating to the climate-controlled spaces 23 and 24. It should beunderstood that although the reference is made to a residentialbuilding, other construction types, such as, for example, a commercialbuilding, a school or a hospital, are within the scope and can benefitfrom the invention. The heated or cooled air is circulated by way of anindoor fan 29 through the climate-controlled spaces 23 and/or 24, forinstance, by way of respective dampers 31 and 32. The comfort HVACsystem 25, including the dampers 31 and 32, is controlled by a control33 so as to maintain predetermined conditions within the rooms 23 and24.

Rather than having thermostats hard wired at fixed locations within theroom 23 and/or the room 24, wireless sensors 34 and 36 are selectivelylocated within the respective rooms 23 and 24 as shown. It should beunderstood that the numerals 34 and 36 may also represent differentpositions of the same wireless sensor. The sensor could, for example, beattached to an individual such as by way of a key chain or the like and,in this case, should be well insulated from the body heat, or could be amovable sensor that an individual can carry from one location to anotherand place it in his/her vicinity within the associatedclimate-controlled space. Such an arrangement allows for the control ofthe comfort parameters such as, for instance, temperature, humidity andcarbon dioxide content, at the point of interest, i.e. where one or morepersons are congregated (e.g. by way of opening and closing specific airregisters or dampers within a climate-controlled space), rather than ata far end of a climate-controlled space (room) where a thermostat mightbe located or even prevent conditioning of the entire building. Itshould be understood that a single sensor may control one environmentalparameter, and multiple sensors may be used to sense environmentalconditions, if desired. On the other hand, a single multi-purpose sensormay control multiple environmental parameters. Further, it may beoperable in association with an occupancy system such that, for example,when a person (or persons) bearing the sensor(s) has been within theroom 23 for a predetermined period of time, the conditions in that roomwould be maintained at the desired comfortable level while theconditions in the room 24 might be allowed to rise or fall outside thecomfort zone or maintained with less precision. If the person(s) thenmoves into the room 24 and remains there for a predetermined period oftime, the controlled conditions in the two rooms could be reversed. Thiswould occur, for instance, by selective operation of the dampers 31 and32 as determined by the control 33 in response to the sensed conditionat the location of the person(s). In this manner, by providing comfortconditions only at the desired locations, the comfort HVAC system 25would consume the least amount of power and operate at high efficiencylevels.

Although described in terms of use in a refrigerated enclosure such as arefrigerated container and a residential split system, the presentinvention is equally applicable to similar refrigeration systems, suchas truck-trailer systems, wending machines, refrigerated displays andmerchandisers, and comfort HVAC systems, such as rooftops and verticallypackaged systems.

While the present invention has been particularly shown and describedwith reference to preferred and modified embodiments as illustrated inthe drawings, it will be understood by one skilled in the art thatvarious changes in detail may be made thereto without departing from thespirit and scope of the invention as defined by the claims.

1. A comfort HVAC or refrigeration system for providing a conditioned environment in a climate-controlled space comprising: cooling and/or heating components for providing a conditioned environment in the climate-controlled space; at least one remote positionable wireless sensor for sensing an environmental condition within the climate-controlled space; a transmitter associated with said remote positionable wireless sensor for transmitting a signal representative of said sensed environmental condition; and a control with an associated receiver for receiving said transmitted signal and for controlling said cooling and/or heating components of said comfort HVAC or refrigeration system in response thereto.
 2. A comfort HVAC or refrigeration system as set forth in claim 1 wherein said sensed environmental condition is at least one of a temperature condition, a humidity condition and a carbon dioxide content condition.
 3. A comfort HVAC or refrigeration system as set forth in claim 1 wherein said at least one remote positionabe sensor comprises a plurality of sensors positioned in different locations within the climate-controlled space.
 4. A comfort HVAC or refrigeration system as set forth in claim 1 wherein said at least one remote positionable sensor comprises a primary sensor for said comfort HVAC or refrigeration system.
 5. A comfort HVAC or refrigeration system as set forth in claim 1 wherein said at least one remote positionable sensor comprises an auxiliary sensor for said comfort HVAC or refrigeration system.
 6. A comfort HVAC or refrigeration system as set forth in claim 1 wherein said at least one remote positionable sensor comprises a multi-purpose sensor to sense multiple environmental parameters associated with said environmental condition in the climate-controlled space.
 7. A comfort HVAC or refrigeration system as set forth in claim 1 wherein said transmitter and said receiver communicate by way of radio frequency signals.
 8. A comfort HVAC or refrigeration system as set forth in claim 1 wherein said cooling and/or heating components comprise a comfort system which includes at least one of air conditioner, a heat pump and a furnace.
 9. A comfort system as set forth in claim 8 wherein at least one remote positionable wireless sensor is adapted to be associated with an individual or with a group of individuals.
 10. A comfort system as set forth in claim 9 wherein at least one remote positionable wireless sensor is adapted to be attached to an individual.
 11. A comfort system as set forth in claim 8 wherein said control communicating with at least one remote positionable wireless sensor is also in communication with at least one occupancy sensor positioned within the building.
 12. A comfort HVAC or refrigeration system as set forth in claim 1 wherein said cooling and/or heating components comprise a refrigeration system for providing refrigerated air to a cargo space.
 13. A refrigeration system as set forth in claim 12 wherein said at least one remote positionable wireless sensor is placed within the refrigerated cargo or in the proximity of the refrigerated cargo.
 14. A refrigeration system asset forth in claim 12 wherein at least one of air temperature, airflow and airthrow is controlled in response to the sensed temperature received from said at least one remote positionable wireless sensor.
 15. A refrigeration system as set forth in claim 12 wherein at least one remote positionable wireless sensor is a plurality of sensors to sense at least one of the temperatures and the temperature differences within the refrigerated cargo or in the proximity of the refrigerated cargo.
 16. A method of conditioning an environment of a climate-controlled space, comprising the steps of: providing cooling and/or heating components of a comfort HVAC or refrigeration system for delivering conditioned air to the climate-controlled space; locating at least one remote positionable wireless sensor and an associated transmitter within the climate-controlled space; with the remote positionable wireless sensor, sensing an environmental condition within the climate-controlled space and transmitting a wireless signal representative thereof; and receiving the wireless signal and responsively controlling said cooling and/or heating components of said comfort HVAC or refrigeration system to maintain a desired environmental condition in the climate-controlled space.
 17. A method as set forth in claim 16 wherein said sensed environmental condition is at least one of a temperature condition, a humidity condition and a carbon dioxide content condition.
 18. A method as set forth in claim 16 wherein said at least one remote positionable sensor comprises a plurality of sensors positioned in different locations within the climate-controlled space.
 19. A method as set forth in claim 16 wherein said cooling and/or heating components comprise a comfort system which includes at least one of an air conditioner, a heat pump and a furnace.
 20. A method as set forth in claim 19 wherein at least one remote positionable wireless sensor is adapted to be associated with an individual or with a group of individuals.
 21. A method asset forth in claim 19 wherein said control communicating with at least one remote positionable wireless sensor is also in communication with at least one occupancy sensor positioned within the building.
 22. A method as set forth in claim 16 wherein said cooling and/or heating components comprise a refrigeration system for providing refrigerated air to a cargo space.
 23. A method as set forth in claim 22 wherein said at least one remote positionable wireless sensor is placed within the refrigerated cargo or in the proximity of the refrigerated cargo.
 24. A method as set forth in claim 22 wherein at least one of air temperature, airflow and airthrow is controlled in response to the sensed temperature received from said at least one remote positionable wireless sensor.
 25. A method as set forth in claim 22, wherein said at least one remote positionable wireless sensor is a plurality of sensors to sense at least one of the temperatures and the temperature differences within the refrigerated cargo or in the proximity of the refrigerated cargo. 